Adjustable shotgun choke device



"urn" United States Patent O M ce 3,161,979 ADJUSTABLE SHOTGUN CHOKEDEVICE Charles E. Lowe, West Hartford, Conn., assigner to Hartford GunChoke Co., Inc., Newington, Conn., a corporation of Connecticut FiledAug. 11, 1961, Ser. No. 130,905

2 Claims. (Cl. 42--79) The present invention relates to adjustableshotgun choke devices.

Among those owning semi-automatic or pump or slide action Shotguns,adjustable choke devices have been well accepted as they enable a singlebarrel shotgun to be quickly and easily adapted to meet the requirementsof all types of shooting by varying the amount of choke. These devicesare commonly provided with slots arranged and disposed so that they havethe added advantage of functioning to reduce the recoil. It has beenrecognized that chokes affect shot patterns and the general objective ofthis invention is to provide shotgun choke devices that enable bettershot patterns and shorter shot strings to be obtained with greateruniformity regardless 'of the choke setting.

In accordance with the invention, this objective is attained byproviding a shotgun choke device including a tubular element attachableat one end to the muzzle of a shotgun barrel and having, at its otherend, a plurality of forwardly disposed resilient choke lingers which arecircumferentially spaced to provide intermediate slots. A sleeve isthreaded on the element and has a forwardly and inwardly taperingshoulder engageable with the lingers as the sleeve is threaded on theelements and the shoulder is operative to force the ends of the ngersinwardly. The sleeve has a plurality of apertures overlying the slots inthe element and operative, in any setting 'of the choke device, to ventthe barrel rearwardly of but closelyadjacent the shoulder of the sleeve.Such venting, being in the choke area, results in improved patterns andshorter shot strings being uniformly attained regardless of the chokesetting.

In the accompanying drawings, there are shown illustrative embodimentsof the invention from which these and other of its objectives, novelfeatures, and advantages will be readily apparent.

In the drawings:

FIGURE 1 is a side elevation of a choke device in accordance with theinvention shown as installed on the muzzle of a shotgun barrel with thedevice adjusted for one position of use, i

FIGURES 2, 3, and 4 are sections taken approximately along the indicatedlines 2 2, 3 3, and 4 4, respectively, of FIGURE 1,

FIGURE 5 is a View similar to FIGURE l but illustrating anotherembodiment of the invention and adjusted for another position of use,

FIGURE 6 is a side elevation of a sleeve that may be vused in place ofthe sleeve of the device shown in FIGURES l through 4, and,

FIGURE 7 is a section taken approximately along the indicated lines 7 7of FIGURE 6.

In accordance with the invention, a tubular element 10 is threaded ontothe muzzle of a shotgun barrel 11 and has a front sight 12. The element10 has an intermediate, exteriorly threaded portion 13 of reduceddiameter and a front portion provided with a plurality of circumferen ti ally spaced, longitudinally disposed, open-ended slots 14 defining aseries of forwardly disposed, resilient choke lingers 15 of arcuatecross section with each linger shown as having a forwardly and inwardlytapering shoulder 16.

A sleeve 17 has the rear part of its bore threaded as at 18 to enable itto be attached to the threaded portion 13 of the element. The rear endof the sleeve bore is 3,161,979 Patented Dec. l22, 1964 counter-bored to.provide an annular skirt 19 overlying the element 10 adjacent thethreaded portion 13. In the intermediate part of the bore, there is aforwardly and inwardly tapering or cone portion deiningfa shoulder 20.

It will be apparent that as the choke device is assembled by threadingthe sleeve 17 on the portion 13 of the element 10, the shoulders 16 and20 engage until the ends of the fingers 15 are forced inwardly fromtheir normal position to the desired extent. In theirnormal Iposition,the lingers 15 define a cylinder and when they are forced inwardly tothe maximum extent,usually with their free ends in marginal contact, afull choke position is effected. Desired intermediate choke positionsare provided such as so-called improved and modified positions.Additional positions are also provided, one between each successive twoof the above referred to major positions. A ring 21 of resilient stockencircles the sleeve 17 and has one end 22 inturned to extend through ahole V23 to engage with the forward part of the element 10 to functionas a click detent as it yieldably catches in the slots 14 as the sleeve17 is turned. In practice, there are six slots 14 and six chokepositions ranging from cylinder to full choke. These positions aremarked on the sleeves (see FIGURES l and 5) and are readable withreference to the front sight 12.

The sleeve 17 has a plurality of apertures located both forwardly andrearwardly of the sleeve shoulder 20. These are shown as` consisting ofa plurality of axially spaced series of transversely disposed slots 24,each series having three slots each, preferably, of alength greater thanthe width of a choke finger 15 and arranged so that each overlies twoelement slots 14 in any choke position and with corresponding slots ofalternate series in alignment. One of the series of slots 24 rearwardlyof the shoulder 20 is close thereto and is shown as extendingtherethrough in the cone rearwardly of its crest.

In the embodiment of the invention illustrated by FIG- URES 6 and 7, theelement 10 is provided with a sleeve 17A which is identical to thesleeve 17 except that its shoulder 20A is at the forward end thereof. Inthe embodiment shown in FIGURE 5, the sleeve 17B has its slots 24Btransversely disposed and arranged as a plurality of axially spacedseries with the corresponding slots of each series being in alinement.

It is the rearward slots that are the most important feature of theinvention. It will be noted that in any operative position of the chokedevice, even in the full choke position, the slots 14 are open. Byproviding slots rearwardly of the sleeve shoulders, gas is ventedrearwardly of the ends of the lingers 15 which define the muzzle of thebarrel. While the impingement of gas streams on the leading walls of thetransverse sleeve slots is effective to reduce recoil, the venting ofthe choke area results in important improvement in shot patterns andshorter shot strings since it minimizes the effect of the choke on thegas streams passing therethrough.

I claim:

1. In a shotgun choke device, a tubular element attachable at one end tothe muzzle of a shotgun barrel and including at the other end aplurality of forwardly disposed, resilient choke lingers, said lingersbeing circumferentially spaced to provide intermediate slots, the outersurface of the free extremities of each finger including a forwardly andinwardly tapering end portion,

and a sleeve closely fitting over said lingers with its rear enclthreaded on said element rearwardly of said fingers and including aforwardly and inwardly tapering, internal shoulder engageable with saidlinger end portions where- Y by, as said sleeve is threaded on saidelement, said fingers are forced inwardly and away from said sleeve toprovide a choke effect and an annular space between the fingers and thesleeve, the width of said slots at the free extremities of the fingersdecreasing as they are forced inwardly to increase the choke effect,said sleeve having a plurality of apertures in and rearwardly of saidshoulder and overlying said element slots, the apertures in the shoulderbecoming increasingly operative as Vents therefor as the choke effectincreases.

2. The choke device of claim 1 in which the sleeve includes a forwardportion the inside diameter of which is that of the forward extremity ofthe shoulder, the

forward sleeve portion also having a plurality of apertures.

References Cited in the file of this patent UNITED STATES PATENTS1,892,522 White Dec. 27, 1932 2,656,637 Richards Oct. 27, 1953 2,662,326Powell Dec. 15, 1953 2,663,961 White Dec. 29, 1953 2,759,286 Moore Aug.21, 1956 2,977,702 Schacht Apr. 4, 1961 2,989,815 Hare .Tune 27, 1961

1. IN A SHOTGUN CHOKE DEVICE, A TUBULAR ELEMENT ATTACHABLE AT ONE END TOTHE MUZZLE OF A SHOTGUN BARREL AND INCLUDING AT THE OTHER END APLURALITY OF FORWARDLY DISPOSED, RESILIENT CHOKE FINGERS, SAID FINGERSBEING CIRCUMFERENTIALLY SPACED TO PROVIDE INTERMEDIATE SLOTS, THE OUTERSURFACE OF THE FREE EXTREMITIES OF EACH FINGER INCLUDING A FORWARDLY ANDINWARDLY TAPERING END PORTION, AND A SLEEVE CLOSELY FITTING OVER SAIDFINGERS WITH ITS REAR END THREADED ON SAID ELEMENT REARWARDLY OF SAIDFINGERS AND INCLUDING A FORWARDLY AND INWARDLY TAPERING, INTERNALSHOULDER ENGAGEABLE WITH SAID FINGER END PORTIONS WHEREBY, AS SAIDSLEEVE IS THREADED ON SAID ELEMENT, SAID FINGERS ARE FORCES INWARDLY ANDAWAY FROM SAID SLEEVE TO PROVIDE A CHOKE EFFECT AND AN ANNULAR SPACEBETWEEN THE FINGERS AND THE SLEEVE, THE WIDTH OF SAID SLOTS AT THE FREEEXTREMITIES OF THE FINGERS DECREASING AS THEY ARE FORCED INWARDLY TOINCREASE THE CHOKE EFFECT, SAID SLEEVE HAVING A PLURALITY OF APERTURESIN AND REARWARDLY OF SAID SHOULDER AND OVERLYING SAID ELEMENTS, THEAPERTURES IN THE SHOULDER BECOMING INCREASINGLY OPERATIVE AS VENTSTHEREFOR AS THE CHOKE EFFECT INCREASES.